Thomas Ross KC

South of the border there have been a number of challenges but in Scotland there are two hurdles for a challenge to the admissibility of evidence, he said.

EncroChat was one of the world’s largest encrypted communications services, with around 60,000 users across Europe and approximately 9,000 in the United Kingdom, as Mr Ross has previously explained.

In exchange for around £1,000 users were provided with a specially modified Android handset. The Spanish manufactured BQ Aquaris X2 is an example of the type of EncroChat handset commonly recovered by law enforcement agencies in the UK, but Samsung and BlackBerry devices were also used.

Prior to sale EncroChat would install its own encrypted messaging program designed to route messages through EncroChat’s own servers and would remove other less secure applications, such as GPS, camera and microphone. 

For an annual subscription cost of around £2,500 per year the user could then exchange text and picture messages with other EncroChat users, apparently safe in the knowledge that the messages could not be intercepted by third parties. A ‘burn facility’ was also provided, allowing users to wipe phone data remotely. 

Of the two hurdles that must be cleared for a successful challenge to the admissibility of evidence, Mr Ross said: “First, the accused would require to persuade the court that the relevant evidence was obtained ‘unlawfully’. A challenge that led to an evidential hearing over many days led to the English Court of Appeal being satisfied that the evidence had been obtained lawfully – although subsequent reports doubt whether the evidence given in that case was completely accurate.

“Second, if the court was persuaded that the evidence had been obtained unlawfully, the accused would have to persuade the court that the irregularity should not be excused.

“This issue is often determined on the basis of good / bad faith on the part of the investigator. If the police obtained the wrong type of warrant in good faith it would probably be excused. If they obtained the wrong type of warrant deliberately — in the knowledge that the correct type might not have been granted - then the evidence might be excluded.”